US3014254A

US3014254A - Hot top

Info

Publication number: US3014254A
Application number: US778141A
Authority: US
Inventors: Ervin A Marcec
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-12-04
Filing date: 1958-12-04
Publication date: 1961-12-26
Anticipated expiration: 1978-12-26

Description

E. A. MARCEC Dec. 26, 1961 HOT TOP Filed Deo. 4, 1958 mc WE E6 Vm mM A. W V R E Stats This invention relates in general to the metal pouring art and more particularly to hot tops. Specifically, it relates to a composite refractory bottom ring for hot tops and method for manufacturing same.

' A hot top is an insulated and inverted funnel-like de vice which is positioned over a mold with its lower end extending slightly into the mouth of the mold. Metal is poured from ladies or the like through such devices and hot tops are particularly employed iu the pouring of iron and steel into ingot molds. It is well known that as molten metal cools and solidifies in a mold it contracts, leaving a trough-like depression in the upper surface of the ingot, billet or other object thus formed. Extensive cropping of the entire upper surface of the molded object to the depth of the depression or cavity thus formed is usually necessary, It is expedient, therefore, to provide above such molds a reservoir of metal in molten condition so that as the metal in the mold chills and contracts, fresh metal will continue to be fed in by gravity, so that ultimately instead of an extensive cavity in the top of the molded article, only a comparatively small riser results after any excess reservoir material has chilled. The cropping of such a riser is a relatively simple matter. Since such a reservoir atop the mold is required to maintain a supply of metal in molten form during the chilling of the article being formed, it is well insulated and thus its name hot top.

Hot tops generally take the form of hollow steel casings provided with a lower inturned lip. This lip is provided to support refractory material which lines the inner walls of the steel casing protecting and insulating the casing. As the lower end of the steel casing of the hot top must be lowered into the mouth of the mold, it is dimensioned so that suitable clearance is provided between the outside of the base of the hot top casing and the mouth of the mold. ternal of the lower inturned steel lip of the hot top casing must also be insulated and protected from the molten metal which rises in the mold just as the inner walls of the casing are protected and insulated, and this is accomplished by means of a refractory ring which is secured to the bottom of the hot top casing.

These refractory rings generally conform in shape to the external outline of the base of the hot top and are provided with a small upwardly extending rim dening a central opening and to protect the internal of the inturned lower lip of the steel casing of the hot top. This refractory rim extends into the casing and approximately abuts the refractory lining of the hot top casing. Such refractory ring devices are suspended by hook-like wire hanger clips, one or two to a side, which hook under the refractory ring and at the other end are inserted into apertures provided for that purpose in the side walls of the steel casing of the hot top. In an effort to prevent metal from spewing out of the mold through the clearance space between the lower end of the hot top casing and the mouth of the mold, the general practice has been to insert or sandwich thin flexible sheet metal wiper strips between the base of the steel hot top casing and the upper surface of the refractory ring with a slightly upturned lip portion extending outwardly to engage the walls of the mold.

ln practice a hot top is prepared for a molding operation by inverting it about external trunnions usually provided on its casing for that purpose. The refractory ring the wiper strips from being pushed too far inwardly between these two surfaces. These generally take the form of a shoulder or other type of identation formed into the upper surface of the refractory ring, and more re- Moreover, the bottom and in cently a metal pin extending into the upper surface of the refractory ring and against which the wiper strip abuts. The hook-like wire hanger clips 'are then applied by first hooking them over the now luppermost bottom surface of the refractory ring through slits in the externally projecting wiper portions, and down the sides of the steel casing into the appropriate apertures. Additional refractory material in the form of grout, referred to as much is then troweled in place to ll the gap between the ring and the lining of the hot top casing, and additional mud may` be troweled over the entire refractory lining of the hot top casing to protect the refractory lining for future pourings, the mud and the refractory ring eing expandable with each operation.

After the mud has dried, the hot top with bottom ring attached is rotated into its normal position and ultimately lowered into the mouth of a mold. It is during this operation that the wiper strips are subjected to outwardly and upwardly directed forces as they engage the walls of the mold, which forces tend to pull them out, buckle them, or otherwise cause their disarrangement and consequently an imperfect seal, This is not diflicult to appreciate when it is considered that the hot top is a heavy and bulky object being handled by crane, and the only forces tending to hold the wipers in place against these forces is that exerted by the hook-like hanger clips referred to above, and which are applied in limited number, usually one or two to a side of the casing,y or in other words, only one or two clips to each individual wiper strip.

The pulling out and otherwise disarrangement of the wiper strips in this still widely used practice results in loss of metal, imperfect molded objects, damage to the thus unprotected outer surface of the steel hot top casing, and substantial hazard to operating personnel.

More recently, in my co-pending application Serial No. 483,322, filed January 21, 1955, I have provided a composite refractory ring in which the thin sheet metal wiper strips are provided with lugs which are depressed into a surface of the refractory ring in a manner such that the collar portion from which the lugs depend overlieS the embedding surface of the refractory material and the flange portion extends outwardly beyond the outer periphery of the refractory ring material. In that application, the wiper strip was preferably attached to the upper surface ofthe refractory material, and after the latter had been formed, rammed, baked, red or otherwise cured, the wiper strip became integrally connected thereto by virtue of the embedded depending lugs.' Conventional hanger clip means, however, were contemplated in that application to suspend such a composite ring from the hot top. l

The use of conventional hanger clips, even with my composite ring device referred to above as copending, is subject to a serious disadvantage. Frequently when these conventional hanger clips are snapped in place, care is not taken by the unskilled foundry labor to insure that the underside of the hanger clips are fully snapped into the recesses provided for that purpose in the underside of the refractory ring. Also, it often happens in careless assembly at the use site that the hanger clip is not positioned properly to pass through the slits in the wiper strips provided for that purpose. In situations like this, not only are the wiper strips likely to be disarranged when the hot top is lowered into the mouth of the mold, but should the original pass result in the setting of the hot top in an improper position, lopsided or at an angle for instance, it is necessary to pull the hot top back up and out of the mold for another pass by the crane, which is supporting it, to position it correctly. It is under these circumstances of withdrawal for repositioning that the wipers are subjected to the most severe crushing forces and likewise severe tensions are put on the hanger clips. Not infrequently, the improperly arranged hanger clips then pull away from the bottom of the ring so that top. These are called hangers `as the ring then hangs in the mold, causing an improper molded product, in

addition to damage to the hot top and danger to the d workmen from spewing hot metal.

The present invention constitutes an improvement over and continuation of my referred-to copending application in that I have now provided for the embedment at least partially of both the metal wiper strips and the hanger clips. Additionally, I have provided hanger clips preferably of spring steel wire formed with a plurality of legs doubling back one over another and which legs are integrally joined by loops thus providing the hanger clip capable of yieldable extendability and limited movement of the free end. One end of these hanger clips is embedded in the refractory material so that it cannot be pulled away, while the other or free end is provided with an inturned hooklike projection adjacent which there is preferably located another loop for ease in handling and directing the projection into engagement with a suitable aperture in the side wall of the hot top casing. In the preferred embodiment, I have provided the collar portions of my wiper strips with a plurality of apertures or holes, and I embed this portion in the outer side walls of the refractory material so that when rammed, the refractory is integrally connected to the embedded wiper strip through the apertures. The embedded end of each of the specially formed hanger clips is also suitably formed, preferably in the form of a hook or loop, so that when it has been inserted also preferably in the outside walls of the refractory material, and above the level at which the collar portions of the wiper strips are inserted, and the refractory is rammed, it too will be integrally connected and embedded therewithin. In the preferred embodiment, it will be seen therefore that the flexible ange portion of the wiper strip extending externally of the refractory requires no slits for the passage of hanger clips and thus an optimum seal is obtained.

With my present invention not only are all of the objections overcome with respect to the tendency for wiper strips and the hanger clips to buckle and pull out or away due to forces acting upon them in the positioning of the hot top within the month of a mold, and which is inherent in nonintegrally connected and nonembedded wiper strips and hanger clips, but I have also now provided a composite device which is fully prefabricated away from the location of use and shipped ready for use, so that all that need be done except for later application of mud internally is to position the composite device inverted over the inverted end of the hot top and to extend and position the integrally attached hanger clips to snap into the respective openings, thus effecting a substantial time and labor saving while assuring an absolute tit and uniform suspension of the refractory ring from the base of the hot top casing.

It is accordingly the principal object of this invention to provide a composite refractory ring for hot tops, in which both the wiper strips and the hanger clips are at least partially embedded and integrally secured to the refractory material so that the possibility of human error the ring is no longer properly suspended from the hot in positioning and suspending same from a hot top is eliminated.

It is another object of the invention to provide the collar portions of the Wiper strips with a plurality of apertures and to embed such collar portions in the refractory material, whereby upon ramming and curing, said wiper strips are integrally attached and connected to the refractory material through the referred-to apertures.

It is still another object of this invention to embed one end of the hanger clips within the refractory material at a level above that at which the wiper strips are embedded.

Yet another object of this invention is to embed both the collar portions of the wiper strips and the lower ends of the hanger clips in the outer side Walls of the refractory ring above its base.

Still another object of the invention is to also provide within said refractory ring additionally embedded reinforcing material integrally connected to the refractory by means of suitable apertures in the reinforcing material.

Another object of this invention is to provide a method for fabricating a composite refractory ring in which both metal wiper strips and hanger clips are embedded at least in part and integrally attached to the refractory material.

These and additional objects and advantages will become more readily apparent from the following descripion taken in conjunction with the accompanying drawings, in which:

FIGURE l is a perspective view of a composite refractory bottom ring for hot tops illustrating a combination in which both metal wiper strips and hanger clips are embedded at least in part and integrally connected to the refractory material.

FIGURE 2 is a section along line 2--2 of FIGURE 1 and illustrates specifically the manner in which the metal wiper strips and hanger clips are embedded within and integrally attached to the refractory material. It also illustrates metal reinforcing embedded and anchored within the refractory material.

FIGURE 3 is a partial elevation viewed along line 3--3 of FIGURE l.

FIGURE 4 is a view similar to that of FIGURE 3 but illustrating a similar portion of the composite refractory bottom ring in place suspended from a corresponding portion of a hot top casing by its embedded and integrally connected hanger clips.

FIGURE 5 is a somewhat schematic sectional view illustrating a composite bottom ring including the ernbedded and integrally connected Wiper strips and hanger clips suspended from the casing of a hot top and Set in place in the mouth of a mold.

Referring now more particularly to FIGURE l, the reference Acharacter 10 generally designates a composite refractory bottom ring for a hot top embodying applicants invention. The refractory bottom ring 10 involves an otherwise conventionally shaped bottom ring of suitable refractory material such as a mixture of silica sands and sodium silicate binder, having a lip-like base 11 which extends laterally outwardly from an opstanding rim 12 which defines a central opening 13. Along the peripheral sides or edges of the base lip 11 of the refractory ring are embedded, preferably one to a side, wiper strips 15 which may be constructed to thin gauge sheet metal material. These Wiper strips are preferably of such length that they meet at the corners the wiper strips from the adjacent sides. These wiper strips include a collar portion 16 (see FIG. 2) provided with a plurality of anchoring means 17, which in the preferred embodiment take the form of cut-outs or holes 17. Extending outwardly and preferably upward at a slight angle from the collar portions 16 are flanges 18 which are preferably integrally attached to the collar portion 16.

In the formation of the refractory material forming the base lip 11 and upstanding rim 12, these Wiper strips are inserted and embedded into the refractory material at least in part, and preferably to the full extent of the collar portions. After the refractory material is rammed in conventional manner, it extends integrally joined above and below the collar portion 16 and through the apertures or holes 17. When the wiper strips 15 have been thus embedded on all lateral sides of the refractory base lip 11 they form, except for a division at the corners, a substantially continuous exible metal wiper or seal extending laterally outwardly and slightly upwardly around the entire external periphery of the base lip. At the same time that the refractory base lip 11 and upstanding rim 12 are being formed, it has been found preferable to insert additional reinforcing material 2G such as thin gauge sheet metal material also provided with a plurality of inter-engaging or securing means such as apertures or holes 21. Thus when the refractory material is rammed in the conventional manner, it too will engage the reinforcing material 20 and be integrally formed therewith through the engaging apertures or holes 21.

There are also additionally provided at the time that the refractory base lip and upstanding rim are formed, a plurality of hanger clips 25, preferably two to a side, which are embedded and integrally attached at one end within the base lip 11 of the refractory material, and preferably in the refractory material at a position above the level at which the collar portions 16 of the wiper strips 15 extend into the refractory material.

The hanger clips 25 (see FIGS. 2, 3 and 4) may be made of any suitable material but are generally formed of steel wire in the order of number l2 size and preferably in the hardness range of spring steel, so that when suitably looped will provide a yieldable, but strong resilient member requiring from about 25 to 50 pounds of pressure to distend. In the preferred form, applicants hanger clips 25 at one end take the form of an inturned hook 26 which is embedded within and integrally connected to the refractory material, and as stated before, preferably above the level at which the metal collar portions 15 of the wiper strips are embedded. External of the refractory member, the hanger clips 25 are preferably provided with at least two somewhat lateral but transversely extending legs integrally interconnected by a loop. As illustrated in FIGURE 2 of the portions external of the refractory material, a first or base leg 27 extends from the embedded hook end 26 laterally external of the refractory base lip to the looped portion 28 which joins it and a second generally lateral and transversely extending leg 29, which preferably doubles back over the lower or first leg 27. Applicant has found it preferable for proper support of the composite refractory ring from a hot top casing, and for ease of connecting thereto, to provide the leg 29 at its lother end with still another loop 3i) from which integrally extends a final leg 31. The leg 31, it will be observed, now somewhat parallels at rest the lower leg 27, and it in turn at its other end is provided with a loop 32 which terminates in a hooklike end 33 bent over the leg 31. The hooklike end 33 is adapted as the clip is stretched or extended to =be inserted or snapped into an aperture 35 (FIG. 4), which is drilled or otherwise formed in the lower portion of the side walls of the hot top casing 36.

The general shape of the preferred form of the hanger clips 25 will be noted to be somewhat in the form of a Z or perhaps more appropriately, because of the looped interconnections of the three legs which fonn a Z, but due to the looped interconnections of the legs, might more accurately approach that of the written capital letter L. The

loops

28 and 30 contribute to the springlike resiliency so that the hanger clip 25 as seen in its relaxed position in FIGURE 3 may be grasped either by the fingers or by means of a suitable instrument, similar for example to the buttonhook, at the loop 32 and stretched or expanded by `application of reasonable pressure, preferably about 35 pounds, to its extended form in which position the hooklike end 33 in inserted and snapped into the apertures 35 in the hot top casing. It will be appreciated that the preferred form of applicants hanger clip provides a considerable degree of latitude of movement of the hooked end 33 vertically and horizontally, so that no difiiculty is encountered in locating and snapping the hooked end 33 into the appropriate aperture 35 in the hot top casing.

Since the general shape of a bottom ring s rectangular and vusually two hanger clips are employed per side, the ring is suspended in' a manner to withstand counter forces should it be necessary to pull the hot top out for repositioning of the order of 275 pounds or more, thus insuring that it will remain properly secured to the hot top.

it will be noted also from FIGURE 3 that in the relaxed position the upper hooklike end 33 of the hanger clips 25 preferably do not extend any higher than the top surface of the 1upstanding rim 12, thus eliminating interference when the rings are stacked or otherwise placed on multiple pallets.

A hot top is rather schematically shown in section in FIGURE 5 and embodies the steel casing of a hot top 36 provided with the apertures 35 referred to above and suitable external trunnions 37, about which the hot top is rotated for preparation as referred to above. Within the hot top casing 36 there is provided a suitable lining of refractory material 3S defining a central opening 39. Below the hot top illustrated in FIGURE 5 there is shown the composite refractory ring as described above suspended from the casing by its integrally connected and embedded hanger clips 25 and with its embedded and integrally connected wiper strips 15 in engagement with the side Walls of the mouth of the mold 40. The refractory ring 10, with its internal opening 13 in register with that (39) of the hot top, thus protects the lower ends of the steel casing 36 from molten metal. For purposes of clarity, no mud is shown troweled into the spaces between the hot top refractory lining and the ring.

After the metal members, such as the wiper strips 15, the reinforcing strips 20, and the hanger clips 25, have been positioned within the shaped refractory material forming the refractory base lip 11 and upstanding rim 12 of the bot-y tom ring 10, the refractory material is rammed in conventional manner whereby it is densiiied and the metal members are firmly embedded therein. Thereafter, the entire composite is baked, fired, or otherwise cured also in well known and conventional marmer. As pointed out earlier and well known in the art, the refractory material is preferably a combination of silica sands `and water glass binder, and the baking and curing is generally accomplished in an oven. at temperatures in the range of 50() to 800 F. and preferably at about 650 F.

Upon completion of the curing period, the composite ring described above is a completely integrated and unitary assembly, such that neither the embedded and integrally connected wiper strips 15 nor the hanger clips 25 will become dislodged `from the refractory material during shipment or use.

It will be appreciated that numerous modifications and arrangements will be hereby suggested to those skilled in the art. For example, different Iforms of hanger clips and different positions of the wiper strips 15 relative to the base or top surface of the refractory base lip. It is also conceivable, by revising the shape of the bottom leg at least of the hanger clips 25, to embed them below the level at which the wiper Strips 15 are embedded within the refractory base lip by providing suitable laterally extending slits in the externally and slightly lupwardly projeco ing ange portions of the wiper strips. These and all auch modifications 'and arrangements as come within the spirit of this invention are included within its scope as best defined in the appended claims.

1 claim:

l. A composite refractory and metal device `for hot tops comprising the combination with a refractory member having a base and a plurality of external sides transverse to said base, of a corresponding plurality of wiper strips comprising relatively thin gauge sheet metal having an inner collar portion provided with means for interengaging with the material of the refractory member, said inter engaging means comprising substantial rlat surface areas embedded within said external sides of said refractory member above the base and permanently bonded to said refractory member and a liexible portion integrally connected to and extending outwardly from said collar portion beyond the external sides of said 'refractory member, and a plurality of yieldably extendable hanger clips each having at least a pair of overlapping legs joined by an integrally formed loop, an end embedded within and integrally attached to a surface of said refractory member below its upper surface, and the other end provided with means for securing it to the hot top, said other end being universally adjustable within predetermined limits.

2. A composite refractory and metal device for hot tops comprising the combination with a refractory member having ta base and a plurality of external sides transverse to said base, of a corresponding plurality of wiper strips comprising relatively thin gauge sheet metal having an inner collar portion, a port-ion at least of which is embedded within and permanently bonded to said refractory member and a exible portion extending outwardly from said collar portion beyond the external sides of said refractory member, and a plurality of yieldably extendable Wire hanger clips each having an end embedded within and integrally attached to a surface of said refractory member below its upper surface, the other end provided with a hook-like projection extending inwardly over said refractory member for securing it and 'the wiper embedded refractory to the hot top, and an intermediate portion between the embedded end and the hook-like projection integrally joined therewith by at least one complete loop, said other-end being universally adjustable within predetermined limits.

3. A composite refractory and metal device for hot tops comprising the combination with a refractory member having a base and a plurality of external sides transverse to said base, of a corresponding plurality of wiper strips comprising relatively thin gauge sheet metal having an inner collar portion, a portion at least of which is embedded and permanently bonded to said refractory member and a flexible portion extending outwardly from said collar portion beyond the external sides of said refractory member and a plurality of yieldably and extendable spring steel wire hanger clips each having a shaped end embedded within and integrally attached to a surface ofsaid refractory member below its upper surface, said clips having at least two legs of said clips external of said refractory member, one extending outwardly and up` wardly from said embedded end, and a second leg of said clips doubling back over said first leg and joined thereto by an integrally formed loop, and Ia hook-like projection on the free end of said hanger clips for securing said wiper embedded refractory to the hot top, said free end being universally adjustable within predetermined limits.

4. A composite refractory and metal device for hot tops comprising the combination with a refractory member having a base and a plurality of external sides tra-nsverse to said base, of a corresponding plurality of wiper strips comprising relatively thin gauge sheet metal having `an inner collar portion, a portion atleast of which is embedded within and permanently bonded rto the side walls of the refractory member and a flexible portion extending outwardly from said collar portion beyond the external sides of .said refractory member, and a plurality of yieldable and extendable spring steel Wire hanger clips each having a shaped end embedded within and integrally attached to a surface of said refractory member below its upper surface, a lirst leg of said clips external of said refractory member extending outwardly and upwardly from said embedded end, a second leg of said clips doubling back over said first leg and joined thereto by an integrally formed loop, a third leg -of said clips doubling back over said second leg and joined to said second leg by another integrally formed loop, -and a hook-like projection on the free end of said third leg for securing said end and the wiper embedded refractory member to the hot top, said hook-like projection being joined to said :third leg by an integrally formed loop for engagement by a finger or tool to extend said clip and position the hooklilre projection to engage the hot top, said free end being universally adjustable within predetermined limits.

5. Method of manufacturing a composite refractory and metal device for hot tops comprising the steps of mixing particulate refractory material with a binder, forming said refractory and binder material into a ring having a base, external sides transverse to said base and an upturned rim defining a central opening, punching apertures in a portion of each o-f a plurality of metal wiper strips, embedding and permanently bonding said aper- -tured portions of -said plurality of wiper strips in the external sides of said refractory material, form-ing yieldably extendable hanger clips of wire with at least two overlapping legs joined by an integral complete loop, embedding one end o-f said yieldably extendable hanger clips in `surfaces of said refractory material below its upper surface, ramming said refractory material about said por- `tions of .the wiper strips and hanger clips extending into the said respective surfaces of the refractory material to firmly embed them the-rewithin, and curing said refractory to integrally attach said embedded portions of the Wiper strips and hanger clips thereto.

6. Method of manufacturing a composite refractory and metal device for hot tops comprising the steps of mixing particulate refractory material with a binder, forming said refractory and binder material into a ring having a base, external sides transverse to said base and an upturned rim defining -a central opening, punching apertures in a 4portieri of each of a plurality of metal wiper strips, embedding and permanently bonding said apertured .portions of said plurality of wiper stirpe in the external sides of said refractory material above the base, for-ming yieldably 'extendable hanger clips of wire with tat least two 'overlapping legs integrally joined by a complete loop, each such hanger clip having formed thereon a hooked free end an an end adapted for anchoring in the refractory material, embedding and permanently bonding in said side walls of said refractory material extending below its upper surfaces including said central opening the non-hooked ends of yieldably extendable hanger clips `in said refractory material, ramming said refractory ma# terial about said portions of the wiper strips and Ihanger clips extending into the refractory material to permanently bond/them and firmly embed them therewithin and curing said refractory to integrally attach said embedded portions of 'the wiper strips and `hanger clips thereto.

References Cited in the file of this patent UNITED STATES PATENTS Marcec Dec. l, 1959